Bolt holding wrench



April 21, 1959 G. s. WING 2,882,773

BOLT HOLDING WRENCH Filed June 10, 1957 2 Sheets-Sheet 1 2 33 F/G. 4,F/GZZ [III //I/ INA/5N 709,

650/?65 6. WING April 21, 1959 G. s. WING BOLT HOLDING WRENCH 2Sheets-Sheet 2 Filed June 10, 1957 F/G. 6 /42 /57 A58 INVENTOR, 650/?655. W/A/6 By w WA fi7'TORNEY United States Patent BOLT HOLDING WRENCHGeorge S. Wing, Palos Verdes Estates, Calif., assignor to Iii-ShearRivet Tool Company, Torrance, Calif., a corporation of CaliforniaApplication June 10, 1957, Serial No. 664,634

3 Claims. (Cl. 81-56) ice a shoulder 31 facing toward the passage 26. Acoil spring 32 biases the drive gear away from the passage 26.

The drive gear 30 meshes with a pinion gear 33 which is journaled inneedle bearings 36 in part 22 of the frame and needle bearings 35 inpart 21 of the frame. The pinion gear has teeth 34 and 37 which areaxially spaced from each other. The teeth 34 mesh with the teeth on thedrive gear 30, while the teeth 37 mesh with teeth 38 on a socket driveshaft 39.

The socket drive shaft 39 is journaled in a passage 40 through part 21of the frame in needle bearings 41 so as to be rotatable therein. Thesocket drive shaft has a Wrench passage 42 therethrough which isgenerally circular. It has a bearing relief 4211 at its midsection toreduce frictional drag in the passage. A wrench 43 passes I through thesocket drive shaft, and the socket drive shaft tool from damage whichmight occur as the result of excessive torque loads on some of the toolelements.

This invention is carried out by providing a coaxial wrench and socketadapted for rotation relative to each other. By this means, the wrenchcan engage the pin of the fastener, and the socket can engage the collarso as to tighten the collar onto the pin. In the preferred embodiment ofthe invention, the socket rotates, and the wrench does not.

According to a preferred but optional feature of the invention, thewrench is held by frictional clutching means so that it will be turnedby excessive torques which otherwise might damage it.

According to still another preferred but optional form of the invention,either the wrench or the socket is adapted to retract so as to permitthe tool toadvance onto the fastener as the fastener is tightened.

The above and other features of this invention will be fully understoodfrom the following detailed description and the accompanying drawings,of which:

Fig. l is a side view, partly in cross-section, of the presentlypreferred embodiment of this invention, showing a fastener beingtightened thereby;

Fig. 2 is a cross-section taken at line 2- 2-of Fig.- 1;

Fig. 3 is an end view taken at line 33 of Fig. 1;

Fig; 4 is a side view, partly in cross-section, of still anotherembodiment of the invention;

Fig. 5 is-a fragmentary cross-section, taken at line 55 of Fig. 4;

Fig. 6 is a side view, partly in cross-section, of still anotherembodiment of the invention;

Fig. 7 is a partial cross-section taken of Fig. 6; e

- Fig. 8 is a fragmentary side view, partly in cross-section, showinganother means for providing relative axial movement between the wrenchand the socket;

Fig. 9 is a fragmentary side View, partly in cross-section, showing theuse of a modified wrench for tightening a fastener of a, somewhatdifferent configuration from that shown in Fig. -1; and

Fig. 10 is a cross-section taken at line 10-10 of Fig. 9.

The preferred embodiment of this invention is shown at line 7-7 in Fig.1 wherein a tool 20 has a frame which may conveniently be made from twoparts 21 and 22, the parts being joined together when the tool isassembled. A tool drive shaft 23, which may be driven by a drill motor24 that is connected thereto by chuck 25, enters the frame through apassage 26. This passage has a pair of needle rotates free of thewrench. A socket 44 has splines 45 which engage splines 46 on the end ofthe socket drive shaft, which hold the socket with the socket driveshaft for rotation therewith. The socket is provided with a groove 47,and the socket drive shaft is provided with a groove 48. These groovesaccommodate a retainer spring 49 between them which holds the socketaxially on to the socket drive shaft.

The socket has internal collar engaging surfaces 50 which have thegeneral configuration of a collar to he turned on to a pin. Thesesurfaces form a hexagon as shown in Fig. 3.

The socket has a central port 51 which passes the wrench 43therethrough. The socket and the wrench have central axes which coincidewith axis 29.

The protruding end of the wrench has pin-engaging surfaces 53 which mayconveniently be of the Allen-head type, that is, hexagonal, although anyother configuration might also be used which will engage the surfaces ofa recess in the pin of a fastener to be tightened. The central portionof the wrench is round. As best shown in Fig. 2, the wrench is providedwith splines or some other type of interrupted surface such as thehexagonal surfaces 54. These surfaces 54 fit in a clutch socket 55whichclu-tch socket has a hexagonal opening 56 for receiving thehexagonal end of the wrench. The outer surface 57 of the clutch socketmay also conveniently be hexagonal for engaging a clutch band 58. Thisclutch band is provided with a circular peripheral surface 60 which maypreferably have an outwardly convex V shape in cross-section (see Fig.1). This peripheral surface is gripped by a brake 61 of the Prony type,which can be tightened on to the clutch band by a brakeeadjustment screw62 (see Fig. 2). The brake restrains the wrenchand, of course, thedegree of restraint, from restraint which for all practical pur-' posesis total, to relatively easily yielding restraint, is adjustable by theclutch band. The terms frestraint and restrained as used in thisspecification and in the claims. cover all such degrees of restraint ofrotation against the wrench relative to the frame.

The right hand end of the clutch socket 55 has a {hardened insert 63against which a thrust bearing 64 bears. This bearing, which may be aball as shown, is carried in a recess 65 in the drive shaft 23. It willbe seen that the action of the coil spring 32 in moving the drive shaftto the left in Fig. 1 tends to keep the thrust bearing ball firmlybetween and against the drive shaft and the insert 63 of the clutchassembly. This biases the wrench tothe left in Fig. 1.

The clutch socket 57 is axially movable in opposition to the coil spring32 so that he wrench can be moved axially. The clutch assembly and theframe hold the socket drive shaft 39 against making any appreciableaxial movement.

In Fig. 1 there is also shown a fastener for which tool 20 isparticularly suited. A fastener of thisnature is generally used forjoining a pair of bodies 66 and 67 t0- gether. These bodies haveregistering holes 68, 69 respectively, through which an externallythreaded shank of a pin 70 is passed. The pin has a head 71 which bearsagainst .one of the bodies while the threaded end of the pm projectsthroughand beyond the bodies. A collar 72 having 'a shear section 73 anda hexagonal socket engaging section 74 is threaded onto the pin.

This fastener may be provided with a washerSS having an annular flange86, and two flat sides. One flat side bears against body 67, and theother against the collar'72. The Washer has a layer 87, 88 ofsubstantially dry lubricant on both of said flat sides, although thelayer 87 adjacent body 67 is optional. A suitable lubricant for thispurpose is sold by S. C. Johnson & Son, Inc., located in Racine,Wisconsin, under the name #153 Wax Lubricant Tube Draw. This lubricantis provided in an evaporable liquid base. The base evaporates before thelubricantis used as described below, leaving the dry wax.

This is a polar wax which dries to a thin him. The purpose of this filmis to reduce or eliminate the variability of the reaction forces betweenthe collar and the work. When this reaction is constant, then thepre-load on the pin can be accurately controlled by adjusting the torqueapplied to the collar.

In setting this fastener, the wrench 43 is inserted into a recess 75 inthe end of the pin, and the socket 44 engages the hexagonal socketengaging section 74. As can .be seen from the drawings, holding thewrench 43 stationary and turning the socket will cause the collar totighten on to the bolt until sufficient torque is exerted on thehexagonal socket engaging section 74 that the shearsection 73 fails andthe hexagonal section comes free. A more complete description of afastener of this type and its operation is given in my co-pending patentapplicant Serial No. 643,183, filed February 28, 1957, entitledFastener.

In order to expel the sheared-off hexagonal section from its socket, anejector means 76 is provided which comprises a retainer ring 77, withinthe socket, a flanged tubular member 78 surrounding the wrench 43 and acoil spring 79 opposed between the socket and the flange 80 of themember 78. The hexagonal section will force the tubular member 78 backinto the socket while the fastener is being tightened. After the shearsection has failed and the tool withdrawn, the spring 79 will force thetubular member 78 to the left in Fig. 1 so as to eject the hexagonalsection from the socket.

Another embodiment of the invention, utilizing a different type ofclutch means, is shown in Fig. 4. A tool 110 has a frame 111 having aclutch cavity 112 and a shaft passage 113 therein. A socket drive shaft114 is journaled in the shaft passage 113 and has a ring gear betweenthe spur gear 141 and the clutch disc 156.

in-line tool. This tool has a frame 131 which frame is provided withshaft passages '132 and 133. A gear cavity 134 is provided between theshaft passages to accommodate a pair of spur gear pinion shafts 135, 136which are journaled at their two ends in passages 132 and 133respectively. These spur gear pinion shafts each have a pair of spurgears incorporated in their length, spur gears 137, 138 being includedon pinion shaft 135 and spur gears 139 and 140 being incorporated onpinion shaft 136.

A spur gear 141 is journaled in a bearing 142 in the frame and has a lug143 for engagement with a shaft of a drill motor (power drive means145a). A screw 144 provides for retention of the drill motor in theproper location in the neck 145 of the frame. Spur gear 141 makesmeshing and driving contact with spur gears 137 and 139.

Another spur gear 146 is mounted coaxially with spur gear 141 and mesheswith spur gears 138 and 140. Spur gear 146 is integral with a socketdrive shaft 147 which drive shaft extends through a bearing 148 in theframe and receives a socket 149 on its projecting end. The socket driveshaft 147 has a wrench passage 150 extending axially therethrough so asto receive a wrench 151. The wrench and the socket have a common centralaxis 152.

The wrench is provided with pin engaging surfaces 153 on its end whichmay form a hexagonal prism so as to form an Allen-head wrench ifdesired. At its other end the wrench is provided with a tapered head 154which is tapered so as to fit into a circular tapered recess 155 in aclutch disc 156. The thickness of the head is less than the depth of therecess 155. A coil spring 157 is opposed The coil spring is seated in arecess 158 in spur gear 141, and bears against that gear and against theclutch disc so as to force the clutch disc toward the socket.

As can best be seen from Fig. 7, the clutch disc is generallyrectangular and has two arcuate (preferably cir- (see Fig. 5) keyedthereto so that rotation of the ring 'gear as caused by a drive gear 116will turn the socket drive shaft.

The socket drive shaft 114 has a wrench passage 117 therethrough whichaccommodates a wrench 118 having a central circular cylindrical portionterminating at the lower end with pin engaging surfaces 119 whicharepreferably hexagonal in the shape of the well known Allenhead wrench.The wrench has a shoulder which rests upon the socket drive shaft tolimit the downward movement of the wrench. At the upper end of theWrench there is integrally attached the lower contact plate 121 of anover-riding clutch 122. A matching upper contact plate 123 is heldagainst the contact plate 121'by pressure exerted from a leaf spring 124against a shaft to which the upper plate is attached. Shaft 125 ishexagonal, and thereby keyed into a hexagonal passage 126 so that itisheld against rotation but is axially movable against the force of thespring 124. An ejector means 76 is provided in the socket in the samemanner as in the tool of Fig. 1, and'like reference numerals are used.

Fig. 6 shows a tool which is particularly suitable foruse with a drillmotor, inasmuch as it is an entirely cular) cut-outs 159, 160 which bearagainst the spur gear pinion shafts 135 and 136, respectively. Thesecut-outs prevent the clutch disc from rotating in the frame.

An ejector means 76 (not shown) can be provided in the socket in thesame manner as in the device of Fig. 1.

In all of the aforesaid embodiments, provisions have been made for thewrenches to be axially movable while the socket is held substantiallyaxially immovable. In general when installing the fastener of the typeshown in Fig. 1, such an arrangement is .to be preferred both for themost eifective tightening of the fastener and for simplicity of toolconstruction. However, sometimes it may occur that a retractable socketand a non-retractable wrench is to be preferred. In Fig. 8, such adevice is shown. A wrench may be substituted for the wrench in any ofthe above tools, and be keyed so that it cannot move axially, althoughit can be turned. A socket drive shaft 166 may also be substituted forthe corresponding part in the above tools. The socket drive shaft isprovided with a tubular portion 167 within which a socket 168 isslidably disposed. A coil spring 169 is opposed between the tubularportion 167' and the socket 168 so as to force the socket away from theframe. A pair of pins 170, 171 projects into the tubular portion andalso into axial slots 172, 173 respectively in the socket. The-socketwill thereby turn with its drive shaft, and can slide axially therein.

Collar engaging surfaces 174 are provided inside the socket, and thesesurfaces may be provided in an hexagonal pattern if desired. The socketand the wrench have a common central axis 175.

A spur gear 176 is made integral with the socket drive shaft 166 so thatwhen this gear is driven by any desired means, the socket will rotaterelative to the wrench. The wrench may include any of the clutch devicesshown in the above described embodiment.

if desired, an ejector means such as means 76 maybe provided in thissocket as shown. These are identical with the means shown with Fig. 1,like parts bearing identical numerals.

Occasionally, it may be desired to form the fastener with a protrusionon the pin for being gripped instead of a recess. Such a modification ofthe pin is shown in Figs. 9 and 10, wherein the protrusion comprises atongue 180 having a rectangular cross section protruding from the end ofa pin 181. In all other respects the pin can be the same as the pin 70shown in Fig. 1, of course omitting the recess at the end thereof. Acollar 72 identical with that shown in Fig. 1 is to be threaded on tothe pin by a socket 182. A wrench 183 has its end modified with astraight slot 184 for receiving the tongue 180. The socket and the restof the wrench may be made according to any of the above describedembodiments. This device illustrates the fact that the hexagonal shapesprovided on the nut and in the socket and also the Allen-head type endon the wrench are not limitations on this invention. Rather, any desiredpin and collar engaging surfaces may be provided as appropriate to thefastener being tightened.

The operation of these devices will now be described. With respect ofthe device of Fig. 1, the pin will first be inserted in the registeringholes 68 and 69 in the plates 66 and 67. The collar will then be startedupon the pin. The wrench 43 is inserted into the recess in the end ofthe pin and the socket 44 is pushed over the hexagonal portion of thecollar. This action retracts ejector means 76.

Thereafter, the drill motor 24 or other means for tuming the drive shaft23, is powered so as to rotate the same. .This rotation is transmittedby the gear frame from the drive shaft through the pinion 33 to thesocket drive shaft 39. The wrench 43 does not initially rotate becauseit is held by the clutch, and the collar will therefore be turned ontothe pin by the socket, because the wrench holds the pin againstrotation. After the collar has been seated against the body 67, themotor will exert a torque on the hexagonal section until a sufiicienttorque is exerted that the fastener fails at the shear section 73 atwhich time the load is relieved from the socket 44. The tool can then bepulled off of the fastener leaving the remainder of the collar (to theleft of the shear section in Fig. 1) torqued to a value determined bythe yield strength of the shear section. In normal cases this is allthat occurs. However, it sometimes may occur that the shear sectionmight no fail at a torque limit below that which would damage the wrench43. In fact, wrenches have been destroyed by this means in wrenches notinvolving yieldable means for protecting the same. As the tool advancestoward the body 69 when the collar advances on the pin, the wrench willbe forced inwardly against spring 32.

In the tools shown, the clutch is adjusted so as not to yield, butinstead, to restrain the wrench up to torque values needed to set thefastener, and below values which would harm the tool. In the tool ofFig. l, the clutch band begins to shift in the brake 61 at a torquevalue which is determined by the setting of the brake adjustment screw62. The torque exerted on the wrench can therefore never exceed a safevalue, and the wrench is protected against distortion.

The operation of tool 110 shown in Fig. 4 is as follows. The socket 127is placed over the collar, and the wrench 118 is inserted into therecess in the pin. Thereafter the drive gear 116 is turned by powerapplied in any desired manner so as to rotate the socket drive shaft 114and thereby the socket 127, tightened the collar on the pin.

As the socket advances onto the pin the wrench 118 will be forced in anaxial direction upward as shown in Fig. 4. This force is exerted againstthe force of spring 124. This tends both to retract the wrench 118 andkeep the over-riding clutch 122 engaged by forcing the contact plates121 and 123 together. If an overload on the wrench occurs, then theover-riding clutch will slip by virtue of the lands on the contact plate121 and 123 climbing each other in a well understood manner. It will berecognized that contact plate 123 is held against rotation because ofthe hexagonal shape of its shaft 125.

The operation of tool (Figure 6) will now be described. A drill motor(not shown) can be fitted on to the lug 143 and held in place by screw144, whereupon turning the gear train starting with spur gear 141, andending with the spur gear 146 on the socket drive shaft 147 drives thesocket 149 to turn a collar on to a pin in the manner as heretoforedescribed. q

The coil spring 157 presses the clutch disc 156 toward the socket driveshaft. As can best be seen from Fig. 7, the cut-outs 159 and 160 fitaround the shafts of the spur gear pinions so that the clutch disc isnot rotatable. It will also be appreciated that the thickness of thehead 154 of the wrench is less than the gap of the circular taperedrecess 155. Therefore when the spring moves the clutch disc to the rightas shown in Fig. 6 and pressure of the tool against the pin moves thewrench 151 to the left a contact is made between the wrench and theclutch disc which prevents the wrench from rotating at torques less thansome predetermined value.

As' the socket moves along the pin while threading-on the collar, thewrench 151 retracts into the tool, pushing te clutch disc along with it.If a torque overload is exerted on the tool in excess of the torquewhich can be held by the disc, then the wrench simply slips in theclutch and thereby is protected against the damage due to overloads onthe tool.

Occasionally it may be desired to have the socket retract, instead ofthe wrench. This is not ordinarily the situation, but in the event thatit is, any of the above described wrenches may be given a collar or someother type of key to hold it against axial movement while stillpermitting the same slipping rotational movement in the clutch. Then thesocket drive shaft 166 of Fig.- 8 may be substituted for the othersocket drive shaft, and be driven by the spur gear 176 attached thereto,from means such as spur gear 116 in Fig. 4. The socket 168 will engagethe collar in the usual manner, while the wrench is inserted into therecess in the pin.

The socket drive shaft does not appreciably move axially, and neitherdoes the wrench in this device, and they do not move appreciably axiallyrelative to each other. However, the socket 168 does move axially withinthe socket drive shaft in opposition to the coil spring 169. The pins170 and 171 in slots 172 and 173 respectively keep the socket fromturning relative to the drive shaft and cause the socket to berestrained to only axial movement relative to the said drive shaft.

It also may occur that instead of having a projecting end on the wrenchsuch as the aforesaid Allen-head ends for the purpose of extending intoa recess in the fastener, the fastener may instead be provided withmeans such as the tongue shown in Fig. 9, and the wrench will thereforebe given a matching slot 184 for receiving the same. This simplycomprises a modification of the pin engaging surfaces on the end of thewrench and no other alterations need be made in the aforesaid tool forthis purpose.

All of the above tools provide a means for tightening down a threadedfastener particularly a fastener of which a portion is to be torqued offso as to limit the torque applied thereto. In addition these tools areprotected against damage due to torque overloads which otherwise mighttwist the wrench, thereby rendering the wrench useless and perhaps alsodamaging other parts of the tool structure.

This invention is not to be limited by the embodiments shown in thedrawings and described in the description, but only in accordance withthe scope of the appended claims.

I claim:

1. A tool for tightening a threaded fastener in which a collar isthreaded onto a threaded pin comprising: a

frame; a socket drive shaft jonrnaled in the frame and supported :by theframe .for rotation relative thereto; a gearonssaidsocket-drive:shaft;,.a socket member on said socket driveshaft,:saidpsocket member being adapted to -.engage the collar to turn thesame .onto the vpin; a wrench Imember adapted to engage the ,pin .torestrain it from rotation, said wrench :memberpassing through the socketmember, the wrench member being axially movable-irelative-rto the frameand restrained against rotation relative thereto; a tooltdriveshaftjonrnaled to the frame and {axially shiftable relativethereto; bias :means .pressing said L-tool driveshaft toward the wrenchmember; a ,gear on said tool drive shaft, said tool drive shaft, socketmember and wrench member having coincident central axes; a pinion gearlaterally spaced from the aforesaid axes and interconnecting the gear onthe tool drive shaft withthe gear on the socket drive shaft, the gearson the tool drive shaft and the pinion gear being of sufficient axiallength 'to permit relative sliding between them while the said gearsremain enmeshed; and bearing means dis- ;posed between the tool driveshaft and the wrench member enabling the tool drive shaft to rotate.independently'of the wrench member, the bearing means being operative totransmit bias force from the tool drive shaft to the wrench member toaxially shift the wrench member toward a fastener to be engaged by thetool.

2. A-tool for tightening a threaded fastener in which a collar isthreaded onto a threaded pin comprising: a frame; a socket drive shaftjournaled in the frame and suppnrted by the frame for rotation relativethereto; a "gear on said socket shaft; a socket member on said socketdrive shaft, said socket member being adapted to engage the collar andturn the same onto the pin; a

wrench member adapted to engage the pin to restrain it :from rotation,said wrench member passing through the socket member, the wrench memberbeing axially movable relative to the frame and restrained againstrotation relative thereto; a tool drive shaft journaled to the frame andaxially shiftable relative thereto; a gear on said tool drive shaft,said tool drive shaft, socket member, and wrench member havingcoincident central axes; a pinion gear having an axis of rotationlaterally spaced from the said axes and interconnecting the gear on thetool drive shaft with the gear on the socket drive shaft, thegear on thetool-drive shaft and the pinion gear being of ,suificient axial lengthto permit relative sliding between them while they remain enmeshed; biasmeans operable on the tool drive shaft and effective to press saidwrench member toward a fastener engaged by the tool; whereby the tooldrive shaft is adapted to rotate independently of the wrench member butis operative with the bias means to axially shift the wrench membertoward the fastener to be engaged.

3. A tool according to claim 2 in which the bias means comprisecompressible springing means disposed between and hearing against thetool drive shaft and the wrench member which press said wrench memberaxially toward a fastener engaged by the tool, and react between thetool .drive shaft and the wrench member as a bearing enabling the tooldrive shaft to rotate independently of the wrench member while exertingan axial "force thereon.

References Cited in the file of this patent UNITED STATES PATENTS

